CFD water spray model development and physical parameter study on the evaporative cooling

Raoult, F.; Lacour, Stéphanie; Carissimo, Bertrand; Trinquet, F.; Delahaye, Anthony; Fournaison, Laurence

doi:10.1016/j.applthermaleng.2018.12.063

Cited by 35 publications

(7 citation statements)

References 44 publications

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“…However, experimental observations suggest that air/water mixture introduced in stream rapidely reach an equilibrium state from which evaporation becomes slow althoug vapour content is far from saturation ( [7], [9], [10]). Numerical simulations confirm evaporative blockage, which results from mechanical, thermal and chemical balances occuring in air-water mixture ( [8], [11]). The exergetic approach offer a clear distinction between the 3 mechanisms involved during evaporation in mixtures to predict cooling efficiency.…”

Section: Introductionmentioning

confidence: 68%

Entropy analysis in spray cooling for dosing water injection

Lacour

Feidt

2022

IOP Conf. Ser.: Earth Environ. Sci.

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Spraying water in air improves air-cooling capacity, which then relies on the evaporation of water. Even for small drop sizes, literature reports that the evaporation remains limited inside the spray and below saturation limits. In this article, we describe the evolution of thermodynamic quantities in a mixture of air and evaporating liquid water. A complete and coherent formulation is used to express enthalpy, entropy and chemical potential. At constant enthalpy, we show that the chemical equilibrium corresponds to an intermediate state in which droplet evaporation is not complete and entropy is maximum under certain conditions. Results are compared with some experimental values measured in a wind tunnel downstream of a spray. The calculated values are consistent with observations. Cooling efficiency is discussed for the various parameters, which are the amount of water, air temperature and ambient humidity. Then, the numerical approach is inverted in order to forecast the amount of water needed to reach a target cooling temperature. This numerical approach is used to set water flow depending on inlet flow conditions and cooling objectives.

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Section: Introductionmentioning

confidence: 68%

Entropy analysis in spray cooling for dosing water injection

Lacour

Feidt

2022

IOP Conf. Ser.: Earth Environ. Sci.

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“…Dry bulb temperature, ambient absolute humidity, air flow velocity, temperature and velocity of droplets are the main operational parameters which influence on the spray cooling performance. A number of papers with experimental [3][4][5][6] or numerical [7][8][9][10] analysis, focused on the investigation of operational parameters impress on the spray cooling performance.…”

Section: Introductionmentioning

confidence: 99%

Thermal analysis on the impact of spray charactristics on evaporative cooling process

Amoli

Ajarostaghi

SEDIGHI

et al. 2022

Journal of Thermal Engineering

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In hot and dry climates, evaporative cooling of the air by water spray can be applied in several requirements, such as evaporative condensers which the airflow is precooled by the water spray before it reaches the condenser. The interaction between water droplets and the air is a complicated two-phase flow that is affected by the several parameters. Here, an Eulerian-Lagrangian 3D model was developed to investigate the influence of important parameters on spray cooling performance in a rectangular duct. The evaluated parameters include the number of nozzles, inlet air flow rate, and spray water flow rate. The results represented that growth in the number of nozzles causes a reduction in the spray cooling efficiency. Thi s is due to decrease of droplets retention time within the duct by increasing the number of nozzles at a constant total spray flow rate in the cases. The maximum and minimum spray cooling efficiency belong to the cases with one nozzle at water flow rate of 20 l/h and four nozzle at water flow rate of 5 l/h, respectively. The difference between spray cooling efficiency at 3 and 4 number of nozzles is less than 1.8%. Moreover, increasing the air flow rate from 0.5 l/h to 2 l/h (by 300%) makes a decrease in the spray cooling efficiency up to 58.6%.

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“…Recently, Computational Fluid Dynamics (CFD) as a method of analyzing condensation phenomenon in wet steam flow is popular with an increasing number of scholars. And CFD is considered as an excellent way for studying experiments with high costs and accurate equipment [19]. The condensed phase can be solved by two methods, namely Lagrangian [20] and Eulerian schemes [21].…”

Section: Introductionmentioning

confidence: 99%

“…Fig 19. The contours of Mach number, mass change rate and wetness fraction of polydispersed model with QMOM approach in turbine blade for back pressure ratio p out /p in * =0.70.…”

mentioning

confidence: 99%